Ceramic materials have long been considered for use in the fabrication of armor components because ceramic materials have a high hardness, are potentially capable of withstanding armor-piercing projectiles, and are relatively lightweight. However, the use of ceramic materials in armor applications has been limited by the low impact resistance of these materials, which results from ceramic's brittleness and lack of toughness. Indeed, one of the significant drawbacks to the use of ceramic materials in armor applications is that they lack repeat hit capability. In other words, ceramic materials tend to disintegrate upon the first hit and cease to be useful when subjected to multiple projectiles. For a more effective utilization of ceramic materials in armor applications, it is necessary to improve the impact resistance of this class of materials.
One method to overcome the disintegration of ceramic armors is to encapsulate the ceramic with a layer of surrounding metal. Such a method is disclosed in U.S. Pat. No. 4,987,033 incorporated herein by reference. However, there are still deficiencies with the encapsulation of ceramic cores in the prior art. First, because of the properties of the proposed metals, conventional casting processes cannot be readily and effectively utilized to encapsulate the ceramic cores. For example, the very high solidification shrinkage of metals (˜6 to 12%) precludes this process as the encapsulating metal exerts undue stresses on the ceramic core and can result in the fracturing of the ceramic. As such more expensive encapsulation processes, such as, powder metallurgy techniques are used as disclosed in U.S. Pat. No. 4,987,033.
Accordingly, a need exists for an armor component formed of an encapsulated ceramic material that has improved impact resistance, and for an inexpensive method for forming an armor component from a ceramic material that has improved impact resistance.